1. Field of the Invention
The present invention relates to methods for making carbon black.
2. Description of the Prior Art
The prior art discloses furnaces for making carbon black which consist of gas and air inlets, one or more oil injectors, a reactor chamber, and quench sections. Furnaces using these elements include those shown in U.S. Pat. Nos. 2,918,353; 3,009,784; 2,616,794; and 3,420,631. Oil feedstock is vaporized and injected into the reaction chamber where an air-gas mixture is combusted. Carbon black particles are formed and pass into a quench section.
The formation of carbon black can be visualized as taking place in three phases: (1) an induction phase in which the hydrocarbons are decomposed into elementary fractions; (2) a phase in which carbon black nuclei are formed; and (3) a particle growth phase in which the carbon black nuclei reacts with other nuclei and with the remaining hydrocarbon fractions. During this third phase, carbon black particles react with gases and other reactive species to produce such side effects as increased carbon monoxide content, oxygen group attachments and porosity. This third phase is ended when the available energy is reduced to a point which will not support further reactions.
The manufacturer has little control over the duration and nature of the processes of nucleation and reaction with the active species and carbon particles.